I believe there is an issue with the Modern theme. I have attempted to switch my server's softaculous theme to Modern (which I think looks great in the pictures), however the leftpanel menu is not loading. Additionally I cannot save the Customize theme settings. Otherwise the theme is working.

The Default theme works fine; installs, removals, updates - no issues. The server is running CentOS 6.5 (Final), Apache+NginX Reverse Proxy, DirectAdmin, PHP 5.5 mod_php. I suspect it could be a DirectAdmin permission error, but everything looks in order: